In the state of the art, tapered slotline antennas (TSAs) are known which are used for determining and/or measuring radiation and signal characteristics of wireless devices over the air (OTA measurements). The tapered slotline antennas are also called Vivaldi antennas. For instance, such tapered slotline antennas can be used for testing devices under test (DUTs) such as communication devices in certain frequency ranges. The tapered slotline antennas may be formed by a printed circuit board having a low thickness.
However, the small thickness of such tapered slotline antennas results in a low mechanical stability. Thus, the risk is high that the tapered slotline antenna gets damaged while using the tapered slotline antenna.
Further, it is known to use a bulky dielectric holder which supports the tapered slotline antenna such that the mechanical stability is improved. However, the bulky dielectric holder influences the radiation performance of the tapered slotline antenna. For instance, reflections occur resulting in side lobes in the radiation pattern which are not desired. These side lobes negatively affect the radiation performance of the slotline antenna.
Besides the tapered slotline antennas standard, gain horn (SGH) antennas may be used which have a higher mechanical robustness.
Accordingly, the antenna units known in the prior art do not have satisfying characteristics regarding their mechanical robustness and radiation performance. Thus, there is a need for an antenna unit having both good radiation performance and mechanical robustness.